The Evolution of Ultrabattery Technology: from Innovation to Long-life, Grid Scale Energy Storage Device

It has long been considered necessary that large-scale energy storage be installed on power grids in developed and developing economies. Storage damps the grid system, reduces its inefficiencies, offsets peaks, reduces fossil fuel loads and creates the opportunity for larger penetration of renewable energy into the grid. However there have been substantial technical, safety, environmental and financial hurdles to the realization of true grid-scale storage and no single technology has been able to present a safe, environmentally palatable solution to suit projects at various scales. The development of a hybrid supercapacitor and lead acid cell – the UltraBattery ® – ten years ago showed that lead acid cells had very much more significant potential than was previously believed possible. When experimental results showed that the cell was further capable of grid-scale smoothing and ancillary support the economics of grid storage suddenly began to shift. This paper explains how a technology envisaged for hybrid electric vehicle use has blossomed into a storage solution with proven multi-MW credentials in grids around the world and describes how mass grid storage may begin to be installed on the kW by kW scale as the market is opened for small to medium enterprises and forwardthinking utilities to install dual purpose backup schemes with the potential to earn revenues in the multi-billion dollar smoothing, shifting, energy retail and grid regulation markets.